Various types of machines employ paper stocks or paper tapes which are transported through the machine utilizing pin-type drives which are engaged in apertures in the paper stock or tape to move it through the machine. A common machine of this type is the conventional computer printed which employs a series of aligned pre-punched holes along each edge of the paper stock, allowing pins projecting from drive sprockets on opposite sides of the printing mechanism to be received in these holes and transport the paper stock positively through the printer. This type of drive obviously eliminates paper slippage and ensures an incremental and positive advance of the paper through the machine. Further, once the paper stock is aligned, the paper stock remains straight as it feeds through the machine and also is maintained in a timed relationship with the printing mechanism so that there is no overprinting of lines one on the other.
Of course, computer printers are by no means the only devices which utilize pin-type drives or transports to positively advance paper stocks therein. For example, labeling devices commonly use pin-type drive transports to incrementally advance and dispense printed labels which are applied to articles to be marked with product or price information. In such devices, a two-layer tape is used, one layer forming the discrete labels and the other forming a backing strip which is used to advance discrete labels in a timed relationship into the printing mechanism and subsequently to advance to the printed label to a position where it can be dispensed.
Normally, label stocks of this type have discrete labels which have an adhesive surface faced against a backing strip so that after the label is printed and the backing strip is advanced, the discrete labels will be released from the backing strip and can be "wiped on" an article requiring price information or product information, such as the Universal Product Code. For information on the latter, see "UPC Symbol Specification", January, 1975, published by Distribution Codes, Inc., 401 Wythe Street, Alexandria, Virginia.
In conventional label stocks, the individual or discrete labels are adhered to the back of the strip, which usually includes a release coating such as a silicone composition, so that the individual labels will easily peel from the backing strip. In many labeling devices, this is accomplished by constructing the label stock of relatively stiff paper and routing the backing strip over a small roller with a sharp change in direction so that label will automatically peel away from the backing strip as the latter passes over the small roller and changes its direction due to stiffness of the label stock. It can be appreciated that for both the printing operations and the dispensing operations, it is necessary that the label stock, and thus the backing strip, be positively advanced in the device in specific increments in order that the label will be in the proper position to print product code or price information, and subsequently advance properly to cause it to peel away from the backing strip, exposing its adhesive surface so that it can be "wiped on" an article requiring the price or product code information.
Due to the necessity for positive and specific incremental advancement of label stocks in labeling devices, the backing strip of stock usually includes pin-type drive apertures which can be engaged by a drive sprocket with projecting pins which are received in the apertures to move the label stock through the unit. U.S. Pat. No. 4,041,863, owned by this assignee, shows a labeling device employing a typical pin-drive sprocket in its transport system and also illustrates the prior art labeling stocks that have been used in such devices.
As is shown in the referenced patent, the prior art backing strip of the label stock included a plurality of die-cut U-shaped apertures thereon that received pins therein on a drive sprocket to transport the backing strip through the device. As the backing strip passes over the drive-sprocket, the pins thereon will be received in the U-shaped aperture and displace the paper blank within the confines of the die-cut forming the aperture. In such die-cut backing strips, it has often been the practice to leave a small web or neck of the backing strip at the apex of the semi-circular portion of the U-shaped die-cut to prevent the paper blank from sticking to the label when it peels away. If the paper blank within such an aperture aggressively sticks to the label, it can cause the backing strip to tear and can obviously rip the backing strip and eliminate subsequent drive apertures, or alternatively, cause the backing strip to separate completely, requiring the operator to re-thread the unit. To reduce the frequency of the blanks' separation from the backing strip, a small web is used to secure the apex of the U-shaped blank. This, however, has not proven satisfactory.
While this invention is intended primarily to correct the problems such as described above in label stocks, it can also be used in other paper stocks utilizing pin-type drive transports. For example, in paper stocks for computer printers which normally use such drives, the holes are completely punched out, eliminating the blanks in these apertures. However, utilizing this invention, it is possible to leave the paper blanks associated with the aperture, thereby eliminating a good deal of paper chaff which would otherwise result when the blanks within the apertures are fully punched out.
In some devices, this chaff from paper stocks utilizing pin-type drives have caused various machine malfunctions, and thus these also could be eliminated if the current invention is applied to such paper stocks.
Also, this invention allows the use of inexpensive dies because it is not necessary for the edges of the cutting die to engage an anvil to completely sever the blank nor to punch out the resulting paper blank. As a result, the die-cutting edges last longer, resulting in further economies.